Snap ring tool



Jan. 29, 1963 J. SALAZAR 3,075,284

SNAP RING TOOL Filed Aug. 25, 1960 F I G 3 INVENTOR.

JULES SALAZA R av 202212 WW A TTORNE Y United States Patent Calif.

Filed Aug. 23, 1960, Ser. No. 51,341 1 Claim. (Cl. 29-229) This invention relates broadly to machine tools and more particularly to an improved tool for removing snap rings.

Snap rings conventionally comprise a split ring structure of spring metal having a square or rectangular cross section. The ring is biased to bring the split end portions together to form a substantially complete circle. In use, the ring is snapped into an annular groove on a shaft or other structure for retaining cooperating components in place. To insert the ring, the split ends are biased apart to circumferentially expand the entire ring structure. The natural resiliency of the ring will then snap it into place after the ends have been placed over the annular groove on the shaft or other structural element.

Removal of snap rings has required the provision of special types of tools. Most of these tools constitute toggle structures in which suitable tongs are provided for engaging the adjacent split ends of the snap ring to urge the ends apart. However, snap rings are sometimes disposed in inaccessible places wherein it is extremely difficult to engage the end-s of the snap ring in order to make effective use of the tongs. In such instances, it is usually necessary to employ a screwdriver or chisel in conjunction with a hammer. This operation requires some skill and if not carried out properly will result in damage to the various components. Moreover, once the snap ring is pried loose, it will tend to snap free and fly off in an arbitrary direction.

With the above in mind, it is a primary object of this invention to provide an improved snap ring tool for facilitating the removal of snap rings.

More particularly, it is an object to provide an improved tool which includes compound working surfaces enabling partial removal of a snap ring and then subsequent removal under controlled conditions so that the snap ring will not arbitrarily fly off from the work.

Another object of the invention is to provide an improved snap ring removing tool which constitutes a single integral member without any moving parts or pivoted portions to the end that it may be manufactured extremely economically.

Briefly, these and many other objects and advantages of this invention are attained by providing a tool in the form of an elongated flat member including at one end portion a curved cutout defined by a curve of varying radius of curvature.

The extreme end of the curved portion terminates in an engaging tip facing generally inwardly towards the initial portion of the curved cutout. With this arrangement and the asymmetrical nature of the curve, there is provided room for receiving a circumferential portion of the snap ring when the engaging tip of the tool is forced against one end of the snap ring.

The opposite end of the flat member constituting the tool is designed with a taper terminating generally in a rounded end which may be readily inserted under an arcuate portion of the snap ring after it has been partially removed to enable controlled prying free of the ring. The thickness of the tool is preferably less than the thickness of the snap ring itself so that one of the longitudinal edges of the tool may be employed to .reinsert the ring.

A better understanding of the invention will be had by referring to a preferred embodiment thereof as illustrated in the accompanying drawings, in which:

FIGURE 1 is a perspective view of the improved snap ring removing tool of this invention;

FIGURE 2 is a side elevation of one end portion of the tool; and,

FIGURE 3 is a perspective view illustrating one use of the tool in conjunction with the removal of a snap ring on an automobile universal joint.

Referring first to FIGURE 1, the snap ring removing tool comprises generally an elongated fiat member 10 including at one end portion a cutout 11. The other end of the tool terminates in a tapered, rounded end portion 12.

The cutout 11 is defined by an initial inwardly curved edge 13 of a first given radius of curvature merging into a second curved edge 14 of a second given radius of curvature shorter than the first given radius of curvature and of the same sign. This second curved portion terminates in an engaging tip 15 facing generally towards the initially curved portion 13 as shown.

With particular reference to FIGURE 2, the manner in which the tool 10 is employed in conjunction with the removal of a snap ring is illustrated. Thus, there is shown a snap ring 16, one split end of which is in engagement with the tip 15 of the tool. The initially curved portion 13 has a radius of curvature indicated at R, and the second curved portion 14 has a smaller radius of curvature indicated at r as described. above. The radius of the snap ring is indicated at R It will be noted that the radius of the snap ring R, is of a value between the large radius of curvature R and the small radius of curvature r.

With the above arrangement, there will be left a small space 17 between the periphery of the snap ring 16 adjacent its engaged end and the second curved portion 14. This space is important and is a direct result of the asymmetrical nature of the cutout. Essentially, the space provides room for the snap ring to expand into when a torque is applied tending to pry the split ends of the ring apart. If a semi-circular type cutout were provided, there would be engagement of all portions of the ring by the curved cutout portion of the tool and proper expansion of the ring could not readily be achieved.

Referring now to FIGURE 3, there is illustrated a particular operation in which the tool 10 is useful. In FIGURE 3, there is shown a universal joint 18 provided with a snap ring 19 adjacent the trunnion structure 20 of the universal joint. In employing the tool 10, the engaging tip 15 is caused to engage one end of the snap ring as shown, and the initially curved portion 13 of the cutout in turn caused to bear against either an arcuate portion of the snap ring itself, or, preferably in the case of the universal joint, part of the trunnion structure 20'.

With the tool engaged as shown, a downward torque may be applied to partially lift the snap ring 19' out of its groove. When the ring has been raised to an extent such that an arcuate portion will lie above the trunnion structure 21' the tool may be carefully disengaged from the end and the opposite rounded end 12 of the tool inserted transversely under the arcuate portion of the ring 19 exposed above the trunnion structure 20. The ring may then be pried upwardly to enable controlled removal of the ring completely from the structure. Because of the narrowed dimension of the end 12, a portion of the tool 10 will pass entirely through the ring so that should accidental snapping loose of the ring occur, it will be ordinarily captured on the tool.

The thickness of the tool 10 is indicated by d in FIG- URE 3 and it will be evident that this thickness is less than the thickness of the snap ring 19. Thus, the longitudinal edges of the tool may be employed for urging the snap ring back into place when it is desired to reassemble the structure.

From the foregoing description, it will be evident that the present invention has provided a greatly improved snap ring removing tool. The overall device is of a single integral structure and may be readily manufactured at minimum expense, there being no toggle or pivoted structures nor any movable parts.

While only one specific embodiment of the snap ring removing tool has been described, the invention is not to be thought of as limited to the exact structure set forth.

What is claimed is:

A snap ring removing tool comprising, in combination: an elongated flat member having a uniform thickness less than the thickness of said snap ring and including at one end portion a curved cutout defined by an initial inwardly curved edge of a first given radius of curvature longer than the radius of said snap ring merging into a second curved edge of a second given radius of curvature shorter than the radius of said snap ring and of the same sign as said first given radius of curvature, said second given radius of curvature terminating in an engaging tip surface facing in an inward direction towards said initially inwardly curved edge for engaging one end of said snap ring, whereby there is defined a space between the periphery of said snap ring adjacent its engaged end and said second curved edge providing room into which said periphery of said snap ring can expand, the longitudinal edges adjacent the other end of said member tapering in-' References Cited in the file of this patent UNITED STATES PATENTS 464,084 Robinson Dec. 1, 491,538 Eno Feb. 14, 1893 631,872 Johnston Aug. 29, 1899 1,515,349 Lossius Nov. 11, 1924, 2,166,089 Brenner July 11, 1939' 2,525,693 Levy Oct. 10, 1950 2,621,550 Bach Dec. 16, 1952 OTHER REFERENCES 0 143,705 Great Britain June 3, 1920 

